This disclosure describes systems and methods directed toward an anti-reversal bearing adapted for use as part of a mud motor to prevent back-driving of the mud motor through the output.
Downhole mud motors have been utilized to drill with a non-rotating drill string using the mud flow to power a mud motor that rotates the drill bit. With the advent of improved drill bits, it has become common to rotate the drill string with a surface drive in unison with the mud motor to achieve higher rotational speeds.
When drilling a well, the drill bit can become snagged or stuck on a subterranean formation. In order to free the drill bit, it may be necessary to apply a very large torque using the surface drive, which can apply more torque than what is typically available from the downhole mud motor. The torque applied by the surface motor is transferred to the mud motor housing and through the mud motor to the drill bit. With a conventional mud motor, the large torque from the surface can exceed the torque capability of the mud motor and may result in backdriving the mud motor, i.e. driving the rotor backwards within the housing, which may damage or destroy the mud motor.
In certain conventional drilling operations, a one-way clutch has been installed in the drill string between the output of the mud motor and the drill bit. Such clutches typically allow a significant amount of reverse motion before the clutch locks. Nevertheless, this reverse motion allows some backdrive of the rotor, which may be damaging to internal elements of the mud motor, and allows the drill string to acquire momentum that, when the clutch locks, will create a large impulse load on the clutch that may limit the operational life of the clutch.